ElevationFilter.java
/* Copyright 2002-2022 CS GROUP
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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package org.orekit.estimation.measurements.filtering;
import org.orekit.estimation.measurements.GroundStation;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.propagation.SpacecraftState;
/**
* Elevation pre-processing filter.
* @param <T> the type of the measurement
* @author Bryan Cazabonne
* @author David Soulard
* @since 10.2
*/
public class ElevationFilter<T extends ObservedMeasurement<T>> implements MeasurementFilter<T> {
/** Elevation threshold under which the measurement will be rejected [rad]. */
private final double threshold;
/** Ground station considered. */
private final GroundStation station;
/**
* Constructor.
* @param station considered by the filter
* @param threshold minimum elevation for a measurements to be accepted, in radians
*/
public ElevationFilter(final GroundStation station, final double threshold) {
this.station = station;
this.threshold = threshold;
}
/** {@inheritDoc} */
@Override
public void filter(final ObservedMeasurement<T> measurement, final SpacecraftState state) {
// Current elevation of the satellite
final double trueElevation = station.getBaseFrame().getElevation(state.getPVCoordinates().getPosition(),
state.getFrame(),
state.getDate());
// Filter
if (trueElevation < threshold) {
measurement.setEnabled(false);
}
}
}